In the field of precision mechanical instruments, the quality of the guide members of certain components, which pivot or oscillate about an axis, is of great importance for the reproducibility over time of measurements made or signals generated. Any defects in the guide members, between, on the one hand, the pivots of a mechanism, and on the other hand, shoulders comprised in an arbor of the component, result in mediocre precision, and also wear and impaired performance over time. The geometric quality of machining operations is a necessary condition for precision operation, but this condition is often insufficient. Indeed, vibration behaviour, in particular in the presence of unbalances, directly affects the pressure applied to the bearings, and therefore lubrication requirements and maintenance requirements, in particular when the bearings and/or pivots are replaced or re-machined to re-establish the quality of the guide members after wear.
A static balancing of the components, returning their centre of mass to the axis of pivoting or oscillation, improves the situation and makes it possible to delay wear. However, the effects caused by inertial defects lead to considerable disruptions in the operation of the mechanism, and the service life over time.